refactor: store error codes in OxcDiagnostic

[DonIsaac]

Instead of inlining error codes into messages (e.g. eslint(eqeqeq): use '===' instead of '=='), they should be stored separately.
This will let us

• configure codes automatically for lint rules
• support hyperlinks in the future

Tasks

First, change OxcDiagnosticInner from

pub struct OxcDiagnosticInner {
    pub message: Cow<'static, str>,
    pub labels: Option<Vec<LabeledSpan>>,
    pub help: Option<Cow<'static, str>>,
    pub severity: Severity,
}

To:

pub struct OxcDiagnosticInner {
    pub message: Cow<'static, str>,
    pub labels: Option<Vec<LabeledSpan>>,
    pub help: Option<Cow<'static, str>>,
    pub severity: Severity,
    pub code_scope: Option<Cow<'static, str>>, // eg `eslint`
    pub code_num: Option<Cow<'static, str>>,   // eg `eqeqeq`
}

Next, update LintContext to set code_scope and code_num before running a rule.

Finally, update all lint rule diagnostics to remove their inlined error codes.

[mysteryven]

• configure codes automatically for lint rules

Could you explain more about this? 🤔